Amperometric biosensors are capable of quantifying trace amounts of biological analytes such as glucose, urea, cholesterol, etc. in biological fluids and foods. Analyte may be electrooxidized directly at the elecrode, or an enzyme may be immobilized on an electrode such that the reaction product of the enzyme with its substrate is detected by an electrical change, e.g. change in current flow, at the electrode. The current generated at the electrode is a function of the quantity of analyte in a sample.
The accuracy of existing amperometric biosensors is compromised by the presence of additional electrooxidizable compounds (hereinafter termed "interferants") present in a biological test sample. Examples of such interferants include ascorbate, urate, bilirubin, cysteine and acetaminophenol.
It would be of great utility to provide a biosensor which would more accurately quantify an analyte without interference from other compounds present in a biological sample.